Raw foodism

This article is about raw food consumption in humans. For a raw diet for cats or dogs, see Raw feeding.

Raw foodism (or following a raw food diet) is the dietary practice of eating only, or mostly, uncooked, unprocessed foods. Depending on the philosophy, or type of lifestyle and results desired, raw food diets may include a selection of fruits, vegetables, nuts, seeds, eggs, fish, meat, and dairy products.[1]

Raw veganism

A raw vegan diet consists of unprocessed, raw plant foods, that have not been heated above 40–49 °C (104–120 °F). Raw vegans such as Brian Clement, Gabriel Cousens, Thierry Browers a.k.a. "Superlight", and Douglas Graham[3] believe that foods cooked above this temperature have lost much of their nutritional value and are less healthy or even harmful to the body.[unbalanced opinion] Advocates argue that raw or living foods have natural enzymes, which are critical in building proteins and rebuilding the body, and that heating these foods destroys the natural enzymes and can leave toxic materials behind. However, enzymes, as with other proteins consumed in the diet, are denatured and eventually lysed by the digestive process, rendering them non-functional.[4] Typical foods included in raw food diets are fruits, vegetables, nuts, seeds, and sprouted grains and legumes.

Among raw vegans there are some subgroups such as fruitarians, juicearians, or sproutarians. Fruitarians eat primarily or exclusively fruits, berries, seeds, and nuts. Juicearians process their raw plant foods into juice. Sproutarians adhere to a diet consisting mainly of sprouted seeds.

Raw animal food diets

Included in raw animal food diets are any food that can be eaten raw, such as uncooked, unprocessed raw muscle-meats/organ-meats/eggs, raw dairy, and aged, raw animal foods such as century eggs, fermented meat/fish/shellfish/kefir, as well as vegetables/fruits/nuts/sprouts/honey, but in general not raw grains, raw beans, and raw soy. Raw foods included on such diets have not been heated above 40 °C (104 °F).[5] Raw animal foodists believe that foods cooked above this temperature have lost a lot of their nutritional value and are less bioavailable.[unbalanced opinion]

Examples of raw animal food diets include the Primal Diet,[6][7] anopsology (otherwise known as "Instinctive Eating" or "Instincto"), and the Raw Paleolithic diet[8][9] (otherwise known as the "Raw Meat Diet").[10]

The "Raw Meat Diet", otherwise known as the "Raw, Paleolithic Diet",[9][11] is a raw version of the (cooked) Paleolithic Diet, incorporating large amounts of raw animal foods such as meats/organ-meats, seafood, eggs, and some raw plant-foods, but usually avoiding non-Paleo foods such as raw dairy, grains, and legumes.[9][10]

A number of traditional aboriginal diets consisted of large quantities of raw meats, organ meats, and berries, including the traditional diet of the Nenets tribe of Siberia and the Inuit people.[12][13][14]

History

Contemporary raw food diets were first developed in Switzerland by Maximilian Bircher-Benner (1867 – 1939), who was influenced as a young man by the German Lebensreform movement, which saw civilization as corrupt and sought to go "back to nature"; it embraced holistic medicine, nudism, free love, exercise and other outdoors activity, and foods that it judged were more "natural".[15]:31–33 Bircher-Benner eventually adopted a vegetarian diet, but took that further and decided that raw food was what humans were really meant to eat; he was influenced by Charles Darwin's ideas that humans were just another kind of animal and Bircher-Benner noted that other animals do not cook their food.[15]:31–33 In 1904 he opened a sanatorium in the mountains outside of Zurich called "Lebendinge Kraft" or "Vital Force," a technical term in the Lebensreform movement that referred especially to sunlight; he and others believed that this energy was more "concentrated" in plants than in meat, and was diminished by cooking.[15]:31–33 Patients in the clinic were fed raw foods, including muesli, which was created there.[15]:31–33 These ideas were dismissed by scientists and the medical profession of his day as quackery.[15]:31–33

Other proponents from the early part of the twentieth century include Ann Wigmore, Norman W. Walker (inventor of the Norwalk Juicing Press), and Herbert Shelton. Shelton was arrested, jailed, and fined numerous times for practicing medicine without a license during his career as an advocate of rawism and other alternative health and diet philosophies.[16] Shelton's legacy, as popularized by books like Fit for Life by Harvey and Marilyn Diamond, has been deemed "pseudonutrition" by the National Council Against Health Fraud.[17]

Leslie Kenton's book Raw Energy - Eat Your Way to Radiant Health, published in 1984, added popularity to foods such as sprouts, seeds, and fresh vegetable juices.[18] The book advocates a diet of 75% raw food which it claims will prevent degenerative diseases, slow the effects of aging, provide enhanced energy, and boost emotional balance; it cites examples such as the sprouted-seed-enriched diets of the long-lived Hunza people and Gerson therapy, an unhealthy, dangerous and potentially very harmful[19][20] raw juice-based diet and detoxification regime claimed to treat cancer.[19]

Claims

Claims held by raw food proponents include:

That heating food above 104–118 °F (40–48 °C) starts to degrade and destroy the enzymes in raw food that aid digestion.[21][22] A few raw food proponents such as Douglas Graham dispute the importance of enzymes in foods, however, and it is commonly believed that enzymes in food play no significant role in the digestive process, prior to being digested themselves.[23][15]:34

That raw foods have higher nutrient and antioxidants values than foods that have been cooked.[15]:34[24] In reality, whether cooking degrades nutrients or increases their availability, or both, depends on the food and how it is cooked.[15]:34[25]

That cooked foods, and especially meat, contain harmful toxins, which can cause chronic disease and other problems, including trans fatty acids produced by heating oil, acrylamide produced by frying, advanced glycation end products (AGEs), and polycyclic aromatic hydrocarbons.[15]:34–5[26] While it is true that a healthy diet minimizes fried food and red meat, not all cooked food contains harmful chemicals (a serving of french fries has 200 times the AGEs of a bowl of cooked oatmeal), and a diet containing a normal mix of cooked and raw food does not shorten life.[15]:34–5[27][28]<[29] High rates of some of these compounds formed by cooking meat can cause cancer in other animals; whether such an exposure causes cancer in humans remains unclear.[27] According to the American Cancer Society it is not clear, as of 2013, whether acrylamide consumption affects people's risk of getting cancer.[30]

Health effects

A meta-analysis clinical trials and epidemiological studies published in 2004, and covering a broad range of cancers, found that it appears that there is an inverse relationship between the risk of developing certain types of cancer and eating both raw and cooked vegetables. Consumption of raw vegetables tended to be associated with decreased cancer risks somewhat more often than consumption of cooked vegetables.[31] On the other hand, a raw food diet is likely to impair the development of children and infants.[32]

Care is required in planning a raw vegan diet, especially for children.[33] Dr. Joel Fuhrman, author of Disease-Proof Your Child, says there may not be enough vitamin B12, enough vitamin D, and enough calories for a growing child on a totally raw vegan diet. Fuhrman fed his own four children raw and cooked vegetables, fruits, nuts, grains, beans, and occasionally eggs.[34]

Food poisoning is a health risk for all people eating raw foods, and increased demand for raw foods is associated with greater incidence of foodborne illness,[35] especially for raw meat, fish, and shellfish.[36][37] Outbreaks of gastroenteritis among consumers of raw and undercooked animal products (including smoked, pickled or dried animal products[36]) are well-documented, and include raw meat,[36][38][39] raw organ meat,[38] raw fish (whether ocean-going or freshwater),[36][37][39] shellfish,[40] raw milk and products made from raw milk,[41][42][43] and raw eggs.[44]

In his book Health or Hoax, nutritionist Arnold E. Bender has written that "Many raw foods are toxic and only become safe after they have been cooked. Some raw foods contain substances that destroy vitamins, interfere with digestive enzymes or damage the walls of the intestine. Raw meat can be contaminated with bacteria which would be destroyed by cooking; raw fish can contain substances that interfere with vitamin B1 (anti-thiaminases)"[45]

A close-up of a raw food dish

Cooking and global warming

It has also been pointed out that cooking food, directly or indirectly, requires energy and may thus release gases associated with global warming.[46] Raw diets mitigate the use of non-renewable resources, which results in raw diets being less environmentally deleterious than cooked food diets in this respect.

Role of cooking in human evolution

Richard Wrangham, professor of biological anthropology at Harvard University,[47] proposes that cooked food played a pivotal role in human evolution. Evidence of a cooked diet, according to Wrangham, can be seen as far back as 1.8 million years ago in the anatomical adaptations of Homo erectus. Reduction in the size of teeth and jaw in H. erectus indicate a softer diet, requiring less chewing time. This combined with a smaller gut and larger brain indicate to Wrangham that H. erectus was eating a higher quality diet than its predecessors.[48] To explain a decreased gut providing the amount of energy required for an increased brain size, Wrangham links his research on the digestive effects of cooked versus raw foods with the lower reproductive abilities of female raw foodists, and BMI in both sexes, to support his hypothesis that cooked starches provided the energy necessary to fuel evolution from H. erectus to H. sapiens.[49]

Theories opposed to Wrangham's include that of Leslie Aiello, professor of biological anthropology at University College London, and physiologist Peter Wheeler. Aiello and Wheeler believe it was soft animal foods, including bone marrow and brains, which contributed to humans developing the characteristics Wrangham attributes to cooked foods.[50] Further, archaeological evidence suggests that cooking fires began in earnest only around 250 kya, when ancient hearths, earth ovens, burnt animal bones, and flint appear regularly across Europe and the Middle East. Two million years ago, the only sign of fire is burnt earth with human remains, which many anthropologists consider coincidence rather than evidence of intentional fire.[51] Many anthropologists believe the increases in human brain-size occurred well before the advent of cooking, due to a shift away from the consumption of nuts and berries to the consumption of raw meat.[52][53][54]

^Cunningham, E (2004). "What is a raw foods diet and are there any risks or benefits associated with it?". Journal of the American Dietetic Association. 104 (10): 1623. PMID15389429. doi:10.1016/j.jada.2004.08.016.